382 



INDEX. 



Testing, Spherical Aberration, 149-158. 



Threads, fine, reflexion of light by, 236- 



239. 

 ,, spiral, drawing of, 302. 



Tolles's Solid Eye-piece, 45. 



Tourmaline, employment of, in polarisa- 

 tion, 309. 



Trifoliutn rubens L. t example of polarisa- 

 tion, 370. 



Tubes, Microscope, length and position of, 

 120-121. 



VALENTIN, Object-stage with double 



Rotation, 319. 

 on Cylindrical Structures, 



352; (note). 



I'rtlonia ^Sgagropil-a Ag., example of po- 

 larisation 370. 



Varnishes, for sealing, 286. 



Vegetable tissues, preservation of, 282-285. 



WATER, air-bubbles in, 191-202. 

 ,, oil-globules in, 202-206. 

 Weleker's Rotating-plate, 316. 

 Wenham's method of determining Angle of 



Aperture, 174-175. 



,, observation of pseud oscopic 

 effect in his dioptric binocular 

 Microscope, 224. 

 Paraboloid, 114 and note. 

 Wire-gauze, images of, as test-objeots, 



127-132. 

 Wollaston on relative distances of 1< 



264-265. 

 Work-table, the, 274. 



OKH: 



